Effects of repeated low-level red light on refractive development during childhood: a systematic review and
Qi Ren1,2, Zhe Chu1,3, Zhengzhi Qiu1
1Department of Ophthalmology, The First Affiliated Hospital, Guangzhou Medical University, Guangzhou, China.
Insights
Repeated low-level red light (RLRL) therapy shows promise in slowing myopia progression in children by reducing axial length and spherical equivalent refractive error. However, its effectiveness diminishes after three months, and impact on corneal curvature is inconclusive.
Area of Science:
- Ophthalmology
- Pediatric Optometry
- Vision Science
Background:
- Myopia is a growing public health concern in children.
- Early intervention strategies are crucial for managing refractive development.
- Low-level red light (RLRL) therapy has emerged as a potential treatment.
Purpose of the Study:
- To systematically evaluate the efficacy of longitudinal repeated low-level red light (RLRL) interventions on refractive development in children.
- To assess the impact of RLRL on axial length (AL) and spherical equivalent refractive error (SER) over 12 months.
- To investigate the dose-response relationship and duration of RLRL treatment effects.
Main Methods:
- Systematic review and meta-analysis of 12 randomized controlled trials (RCTs).
- Searched PubMed, Embase, Web of Science, and CENTRAL databases up to August 2024.
- Employed random-effects models for meta-analyses, including dose-response evaluations.
Main Results:
- RLRL treatment significantly slowed the progression of axial length (AL) and spherical equivalent refractive error (SER) in children.
- Evidence for RLRL's effect on flattening anterior corneal curvature was inconclusive.
- The efficacy of RLRL on AL and SER showed a diminishing trend after 3 months of treatment.
Conclusions:
- RLRL therapy demonstrates a non-linear trend in suppressing axial length development and mitigating spherical equivalent refractive error severity.
- The intervention's efficacy wanes by the third month.
- Further research is needed to clarify the role of RLRL in altering corneal curvature.
Objective:
This study aimed to systematically evaluate the effects of longitudinal repeated low-level red light (RLRL) intervention on refractive development in children over a period of up to 12 months.
Methods:
A systematic search was conducted across four electronic databases, including randomized controlled trials involving RLRL interventions for children. The data covered literature from the establishment of each database up to August 2024. Dose-response meta-analyses were performed using a random-effects model to evaluate the impact of RLRL on refractive development at 1, 3, 6, and 12 months.
Design:
The research is a systematic review and meta-analysis of randomized controlled trials.
Data Sources:
Data were searched across PubMed, Embase (Ovid), Web of Science (WoS), and the Cochrane Central Register of Controlled Trials (CENTRAL) databases from their inception to 3 August 2024.
Eligibility Criteria For Selecting Studies:
Randomized controlled trials comparing RLRL with other pharmacological interventions or no treatment for refractive development in children were included. Independent data extraction was conducted, and study quality was assessed. A meta-analysis was carried out using random-effects models to evaluate the effects of RLRL on refractive development outcomes compared with control groups.
Main Outcomes:
The main outcomes included anterior corneal curvature, axial length (AL), and spherical equivalent refractive error (SER).
Results:
In total, 12 unique RCTs were included. For corneal curvature, evidence for interventions with RLRL treatment being flatter than comparators was lacking (SMD = -0.01, 95%CI -0.19 to -0.12; I 2 = 0, p = 0.76). RLRL treatment was superior to comparators for both AL (SMD = 0.27, 0.06, 0.14, 0.19, 95%CI 0.20-0.33, 0.05-0.08, 0.11-0.17, 0.16-0.23; I 2 = 91, 75, 85, 85%, p < 0.01, respectively) and SER (SMD = 0.62, 0.03, 0.18, 0.32, 95%CI 0.46-0.77, -0.03 to 0.08, 0.12-0.24, 0.24-0.40; I 2 = 91, 75, 85, 85%, p = 0.05 for the 6th month and <0.01 for the remainder) in slowing the progression of myopia during 1, 3, 6, and 12 months. According to the dose-response meta-analysis, the effects of RLRL on AL and SER began to decline after 3 months of treatment.
Conclusion:
RLRL treatment exhibited a non-linear trend, suppressing axial length development and mitigating spherical equivalent refraction severity, with intervention efficacy diminishing by the third month, and the evidence regarding its effectiveness in flattening anterior corneal curvature remains inconclusive.
Systematic Review Registration:
https://www.crd.york.ac.uk/PROSPERO/, Identifier: CRD42024575823.
